US2040899A - Absorption refrigeration - Google Patents

Description

Patented May 19, 1936 PATENT OFFICE ABSORPTION nErmGEaA'rroN Glenn 1*. Zellhoefer, Bloomington, 111.

No Drawing. Application December 11, 1934,

Serial No. 756,982

2 Claims.

The present invention relates generally to a solvent material and a refrigerant mixture for absorption refrigerating machines, both of the two-fluid type and of the three-fluid type.

In absorption refrigeration there is required a solvent material adapted to remain liquid throughout the operation of the apparatus, and a refrigerant material adapts to have a liquid and a vapor phase in the cycles of operation,

adapted to be dissolved or absorbed in the solvent, adapted to be evaporated or boiled as a vapor from the solvent mixture and from the solvent, and adapted to be condensed from the vapor to a liquid. Numerous refrigerants and numerous solvents are known, as well as successful combinations of these.

The two-fluid absorption machines have certain mechanical parts which may be omitted or which are notduplicated in three-fluid machines.

59 In a three-fluid machine, there is in addition to the two-fluid mixture a body of inert gas-which is. always gas, and which does not to any substan tial extent dissolve in any of the components of the two-fluid composition, or in mixtures thereof. as The present invention is directed to a new solvent'for absorption refrigeration, and to combinations thereof with refrigerants. A particular object of the invention is the use of dimethyl ether of triethylene glycol as asol-'- l0 vent.

.Another object is the use of a combination of said solvent with the refrigerant, dichloromonofluoromethane.

Examples of the two-fluid apparatus in which 36 the new solvent material and the new combinationmay be used is disclosed in my co-pending application Serial No. 651,306, filed January 12, 1933, or in my U. S. Patent No. 1,895,698, issued January 31, 1933. Other examples may readily be 40 cited, and will be known to those skilled in the e two-fluid apparatus above referred to, briefly described, comprises a still in which a liquidmixture of solvent and refrigerant is heated to distill away as a vapor the refrigerant material, a condenser wherein said vapor is condensed to a liquid state, an evaporator wherein the resuiting liquid is vaporized at reduced pressure to produce refrigeration, and an absorber in which vapor of the refrigerant material containing added heat units (acquired in the refrigerating process, is again dissolved in the solvent material. Suitable heat exchanging and circulating means are included, and automatic controls may be provided.

The particular characteristics of such a machine are that the still operates at temperatures well above normal temperatures, such for example at 210-to 250 F.; and that the cooling unit operates at temperatures lower than normal, such 5 as from 15 to 50 F. Various parts of the apparatus differ in the prevailing temperatures and pressures, and both pressure and temperature determine the physical state of the free refrigerant material whether gaseous or liquid, and'de- 10 termine the solubility relations between the refrigerant and the solvent material, It is, therefore, very important that the solvent and the refrigerant materials be physically adapted for use as individual materials in certain places and for 15 certain functions, and that they be mutually j adapted for certain functions when they are in combination. Other qualities not essential to re-v frigeration, but pertinent to practical usage, control or limit the choice of solvent or refrigerant, 20 such as odor, viscosity, heat capacity, boiling point, freezing point, volatility, chemical stability, reactivity, corrosive action, inflammability, toxicity, etc.

By considering the limitations herein set forth and suggested, I have been able to utilize dimethyl ether of trlethylene glycol as a solvent, for practical usage, in combination with the refrigerant, dichloromonofluoromethane, which is little known.

The new solvent is herein named as dimethyl ether of triethylene glycol. However, in order to leave no doubt as to its identity, its structuralformula is herein given:

CHaOCHzCHzOCHzCI-IaOCHzCHzOCHs v The refrigerant herein specified is, dichloromonofluoromethane. However, in order to leave no doubt as to its identity, its structural formula is herein given: I

CHClaF In the accompanying claims, the invention is' set forth as a combination useful in absorption refrigeration. It is to be understand that a simple adulteration of the new solvent in its pure form, either by reason of commercial impurities, or by addition of lesser quantities of other material. useful alsoas solvent, is permitted, and such a composition is intended to fall within the scope of the present invention.

This application is a continuation in part of my copending application Serial No. 721,549, filed April 20, 1934, in which the combination with methyl chloride is specific to this application. The solvent herein specifically claimed is covered generically in applicant's later copending application Serial No. 17,064, filed April 18, 1935, as a continuation in part of this application.

What I claim is:

1. A refrigerant mixture for the absorption type of refrigeration apparatus consisting of dimethyl ether of triethylene glycol as the essentially predominant solvent, and dichloromonofluoromethane as a refrigerant.

2. A refrigerant mixture for the absorption type of refrigeration apparatus consisting of dimethyl ether of triethylene glycol as the essentially predominant solvent, and a volatile chemically stable halogenated hydrocarbon refrigerant soluble in said solvent.

GLENN F. ZELLI-IOEFER.